BBC Health Correspondent James Westhead reports

The restrictions mean that most dentists will not be able to offer general anaesthetics in their own surgeries.

They come in guidelines issued at a meeting of the General Dental Council (GDC), the regulatory body for dentists, on Tuesday.

The move follows a number of recent deaths of children having dental treatment under general anaesthesia.

Just last month, 10-year-old Darren Denholm went into a coma and died while having his tooth out.

His mother, Isla Denholm, said: "If he had been in hospital, if he had been there that second quicker, if the dentist had not had to phone an ambulance, maybe if they had been there right there and then at the time when Darren went into cardiac arrest...then maybe they would have saved him."

In future, dentists will only be able to treat patients under general anaesthetic in a hospital or similar setting where there are full emergency back-up facilities.

Specialist doctors

General anaesthesia will only be available if administered by:

• An anaesthetist listed on the General Medical Council's specialist register;
• Trainee anaesthetists in approved training programmes;
• Doctors who are not consultants but who are supervised by consultants from the same hospital.

Every year, 350,000 general anaesthetics are given in dental surgeries, mostly to children. On average there are three deaths a year.

Outside the UK the use of general anaesthesia in dentistry is virtually unheard of.

Specialists have long said that in the rare cases where they are required they should be administered in hospital theatres.

Patient safety

The GDC said that the new measures would "ensure that the correct procedures are in place for monitoring and resuscitating patients, including arrangements for the immediate transfer of a patient to a critical care facility".

GDC President Dr Margaret Seward on BBC Radio 5: "Safety concern"

GDC President Dr Margaret Seward said that guidance on anaesthesia had always been strict, but added that general anaesthesia was never 100% safe in dental work.

"The new guidance will build on this," she said. "It will stress that general anaesthetic should only be considered if there is an overriding clinical need and the alternative methods of pain and anxiety control have been fully explored."

She said the main reason for the new guidance was to "provide for the better protection of the public".

The guidance means that patients requiring general anaesthetic will be referred to a hospital, she said.

"A dentist who has a patient in the surgery who says 'I want treatment under general anaesthesia' must sit down and discuss with the patient the alternatives.

"Then, if necessary - and only then - will they have to refer that patient to a district general hospital, or a specialist clinic in the community - but where the anaesthetic is provided by a consultant anaesthetist."

Hospital specialists will be involved in cases where a general anaesthetic is needed

The council will write to all registered dentists and health service managers to let them know that the guidance takes immediate effect.

The British Dental Association said it supported moves to make dental practice as safe as possible, but expressed concern that the measures would prove expensive.

Dr Anthony Kravitz, spokesman for the association, called for government funds to pay for the re-training of practitioners involved in anaesthesia.

He also said patients concerned about treatment should be aware of the alternatives to a general anaesthetic.